KUCHLER TYPE DESCRIPTION
Kuchler Type: Mosaic of bluestem prairie and oak-hickory forest


PHYSIOGRAPHY : 
The mosaic of bluestem prairie and oak-hickory forest occurs mostly on
hilly or highly dissected terrain [68,69].  Original survey notes for
Kane County, Illinois, noted that the Grand Prairie was bordered by
scattered groves of bur oak (Quercus macrocarpa).  These groves occurred
primarily on hills and other irregular topography [69].  Prior to 1835
in Ogle County, Illinois, uplands to the west of Rock River were
tallgrass prairie with occasional oak groves.  On slopes, prairies
graded into xerophytic oak-hickory forest with more mesophytic forest
types in lowlands [19].  According to Weaver [70], the westernmost
extensions of oak forests (Iowa, southeastern Nebraska, western
Missouri, and Kansas) occurred along creeks and sheltered ravines which
more or less dissect the hilly and rolling portions of the prairie.

The western boundary of the Interior Highlands is nearly level to hilly,
ranging in elevation from 300 to 2,500 feet (90-760 m) [30].


CLIMATE : 
On the Konza Prairie, Kansas, which includes bluestem
prairie-oak-hickory forest mosaic, climate is continental, with hot
summers and cold winters, moderately strong surface winds, and
relatively low humidity.  There are an average of 180 frost-free days
per year, mean annual temperature is 55 degrees Fahrenheit (12.8 deg C),
and mean annual precipitation is 33.4 inches (835 mm).  May and June are
the wettest months, and droughts are frequent [2].

The western boundary of the Interior Highlands has mean annual
precipitation of 32 to 48 inches (800-1,200 mm), mean annual temperature
of 56 to 63 degrees Fahrenheit (14-17 deg C), and a growing season of
approximately 200 days [30].


SOILS : 
Soil colors and textures on prairie sites are very different from
oak-hickory forest sites.  Dark, fine-textured soils predominate under
prairie vegetation, and yellow to red coarse soils occur in forested
areas [16].  In a north-central Missouri prairie-forest tension zone,
soil types are classifed as forest, but have certain prairie
characteristics and are proximate to prairie soils.  Much alternation
between prairie and forest has occurred in this area in the past [42].
A patchwork of prairie, savanna, and open forest occurs on sand deposits
in central Illinois along the Illinois River [8,9].


VEGETATION : 
Where prairie and forest meet, vegetation elements usually intergrade
rather than form distinct edges [17,42].  Weaver [70] described
woodland-prairie contact zones along the Missouri river.  He stated that
bur oak communities were usually but not always bordered by a more or
less continuous community of shrubs [70].  

In north-central Missouri, prairie plants exist in the woodlands of a
study area within the area mapped as bluestem prairie-oak-hickory
mosaic.  Even though forest closure has occurred, groups of prairie
plants still occupy well-drained sites and/or sites with southern
exposures.  Prairie plants on these sites show reduced vigor and scarce
reproduction [42].

No plant species have been identified as unique to the mosaic of
bluestem prairie and oak-hickory forest.  Prairie vegetation is
described in more detail in the bluestem prairie (K074) write-up; its
major components include big bluestem (Andropogon gerardii), little
bluestem (Schizachyrium scoparium), switch grass (Panicum virgatum), and
Indian grass (Sorghastrum nutans) [39].

The composition of oak-hickory forests is discussed in detail in the
oak-hickory write-up (K100).  Kuchler [39] listed white oak, black oak
(Quercus velutina), northern red oak (Q. rubra), bitternut hickory
(Carya cordiformis), and shagbark hickory (C. ovata) as dominants.
Other components in alphabetical order by scientific name include
pignut hickory (C. glabra), white ash (Fraxinus americana), black walnut
(Juglans nigra), black cherry (Prunus serotina), chinkapin oak (Q.
muehlenbergii), basswood, and American elm (Ulmus americana).  In the
northern region other components include northern pin oak (Q.
ellipsoidalis) and shingle oak (Q. imbricaria).  In the southern region
other components include black hickory (C. texana), mockernut hickory
(C. tomentosa), southern red oak (Q. falcata), overcup oak (Q. lyrata),
blackjack oak, Shumard oak (Q. shumardii), and post oak [39].

On the Ozark Plateau in southwest Missouri a mosaic of oak-hickory
forest and glade (grassland with very few trees) occurred in a steep
hilly region.  Dominant glade vegetation included big bluestem, little
bluestem, and switch grass with a few post oak, eastern redcedar
(Juniperus virginiana), ash (Fraxinus spp.), and smoke tree (Cotinus
obovatus).  Old eastern redcedar grow along the ecotone between
oak-hickory forest and the glades [33].

Riparian woods in Iowa consist of cottonwoods and poplars (Populus
spp.), willows (Salix spp.), and bur oak; on upland sites white oak and
shagbark hickory are common dominants.  Both of these types contact
prairie vegetation [24].

Gallery forest within the Konza Prairie, Kansas, is dominated by bur oak,
chinkapin oak, and hackberry (Celtis occidentalis) [2].


WILDLIFE : 
Grasslands are generally considered relatively depauperate in avian
species; conversely, open woodlands are noted for bird species richness.
According to Risser and others [68], there is no clearly distinct
grassland avifauna.  Many grassland species are also found in adjacent
savannas and woodlands or are primarily associated with aquatic
habitats.  For example, two species characteristic of eastern portions
of tallgrass prairie, bobolink (Dolichonyx oryzivorus) and brown-headed
cowbird (Molothrus ater), are more frequently associated with meadows or
ecotonal areas [68].

Wintering birds on the Konza Prairie Research Natural Area, Kansas, were
observed in significantly higher numbers in the gallery forest than in
the prairie.  The red-headed woodpecker (Melanerpes erythrocephalus) was
the most abundant species during 1982 and 1984 in the gallery forest;
black-capped chickadee (Parus atricapillus) was most abundant in 1983.
American tree sparrow (Spizella arborea) was the most abundant species
in the prairie during all three winters.  In all, 30 species of birds
were observed wintering in the gallery forest, and 24 species were
observed wintering in the prairie.  Fifteen bird species were observed
in both prairie and gallery forest, but at different relative
frequencies [32].

Further discussion on wildlife is in the bluestem prairie write-up
(K074) and the oak-hickory write-up (K100).


ECOLOGICAL RELATIONSHIPS : 
Factors Controlling Distribution:  The extent of grasslands is largely
determined by low soil moisture and fire [2,53].  Presettlement
oak-hickory forests were largely confined to sites that experienced fire
less frequently than the surrounding prairie.  Oak groves bordering the
Grand Prairie of Illinois occur primarily on hills and other areas of
irregular topography that provide protection from fires [69].  Both
prairie and forest are destabilized by changes in fire frequency or
intensity [46].  Further discussion on the relationship of fire and fire
frequency to mosaic vegetation is in FIRE ECOLOGY AND MANAGEMENT.

Most upland oak species are adapted to periodic fire, periodic drought,
and poor soils.  Most are at least moderately intolerant of shade [2].

White [58] speculated that at the western limits of the range of sugar
maple in the central states, relatively stable populations of sugar
maple are restricted to ravines, north slopes, and rough topography;
less stable populations that expand and contract with short-term
fluctuations in moisture conditions occur on less protected sites.
Oak-hickory forests occur on sites that experience periodic fire, but
apparently were excluded from sites that experienced annual fire during
the presettlement period [3].

Succession:  Prairie cover occasionally comes into direct contact with
forest cover, especially in the early development of woodlands along
streams.  Usually, however, grassland is replaced by shrubs that extend
outward from the edge of the woodland; shrubs may be replaced by trees
without fire.  Prairie vegetation is shaded out under a closed shrub
canopy [70].  Forest closure eventually displaces prairie species, but
successional rates vary in dissected terrain [15,42].

In the lowlands of the Missouri River, bur oak and chinkapin oak are
mid-seral species.  They are succeeded by northern red oak and shagbark
hickory, which may, in turn, be replaced by basswood and eastern
hophornbeam (Ostrya virginiana) [2].

Related categories for Kuchler Type: Mosaic of bluestem prairie and oak-hickory forest